Version 1.0.9:

Properly fixed the technology to include Bob's Science Pack 4 if bobtech is loaded.
Fixed that the mod's on_tick function wasn't getting re-registered when loading a saved game.
Added a remote interface to allow other mods to detect when an ion cannon is targeted.

Changelog.txt

@@ -56,3 +56,11 @@ Version 1.0.8 - February 26, 2016
 ---------------------------------
 Added Russian translation (thanks to apriori).
 To increase performance, the on_tick function is now only registered upon first launching an ion cannon into orbit - there was no need to run this function in the early game before any ion cannons have been launched.
+
+
+Version 1.0.9 - March 1, 2016
+-----------------------------
+Properly fixed the technology to include Bob's Science Pack 4 if bobtech is loaded.
+Fixed that the mod's on_tick function wasn't getting re-registered when loading a saved game.
+Added a remote interface to allow other mods to detect when an ion cannon is targeted.
+

Readme.txt

@@ -1,7 +1,7 @@
-Orbital Ion Cannon 1.0.8
+Orbital Ion Cannon 1.0.9
 ========================
 
-Version 1.0.8 was released February 26, 2016, was tested using Factorio v0.12.24, and was authored by Supercheese.
+Version 1.0.9 was released March 1, 2016, was tested using Factorio v0.12.24, and was authored by Supercheese.
 
 Do you have a large, late-game megabase and wish there were more cool things you could build? Do you wish you could do more with the rockets you launch than just increment a single number? Do you really hate biters? If so, then this mod is for you!
 Build a giant ion cannon and launch it into orbit with a rocket, wait for it to charge up, and then you're ready to call down the thunder on those pesky aliens.
@@ -21,6 +21,22 @@ This mod also has configuration options available in config.lua. Here you may ad
 -The minimum time between targeting multiple ion cannons
 
 
+Modding Details:
+----------------
+This mod implements a custom event, on_ion_cannon_fired, which can function just like other lua events (https://wiki.factorio.com/index.php?title=Lua/Events).
+In order to use this event in another mod, you should use the following code:
+
+script.on_event(remote.call("orbital_ion_cannon", "on_ion_cannon_fired"), function(event)
+	...
+end)
+
+Where the ... can be any code of your choosing. The following variables are available when using this custom event:
+
+	event.force				The force whose ion cannon is firing
+	event.player_index		The player index of who fired the ion cannon
+	event.position			The position the ion cannon is firing at
+
+
 Credits:
 --------
 

config.lua

@@ -25,7 +25,7 @@ ionCannonExplosionDamage = 500
 HeatupTimeMultiplier = 1
 
 -- When designating an ion cannon target, perform a check to see if any friendly character is too close to the target zone.
--- It is recommended to disable this check if you are using the "Long Reach" mod, since a side effect of that mod causes the radius of this check to excessively increase.
+-- It is strongly recommended to disable this check if you are using the "Long Reach" mod, since a side effect of that mod causes the radius of this check to excessively increase.
 proximityCheck = true
 
 -- The number of gameticks that must pass between designating consecutive ion cannon targets. There are 60 ticks per second, so the default 10 ticks would be 1/6th of a second.

control.lua

@@ -4,8 +4,19 @@ require ("config")
 
 script.on_init(function() On_Init() end)
 script.on_configuration_changed(function() On_Init() end)
+script.on_load(function() On_Load() end)
+
+remote.add_interface("orbital_ion_cannon",
+	{
+		on_ion_cannon_fired = function() return getIonCannonFiredEventID() end
+	}
+)
 
 function On_Init()
+	getIonCannonFiredEventID()
+	if not global.IonCannonLaunched then
+		global.IonCannonLaunched = false
+	end
 	if not global.forces_ion_cannon_table then
 		global.forces_ion_cannon_table = {"player"}
 		global.forces_ion_cannon_table["player"] = {}
@@ -30,18 +41,29 @@ function On_Init()
 			global.goToFull[player.index] = true
 		end
 	end
-	if not global.IonCannonExists then
-		global.IonCannonExists = false
-		for i, force in pairs(game.forces) do
-			if global.forces_ion_cannon_table[force.name] and #global.forces_ion_cannon_table[force.name] > 0 then
-				global.IonCannonExists = true
-				script.on_event(defines.events.on_tick, process_tick)
-				break
-			end
+	for i, force in pairs(game.forces) do
+		if global.forces_ion_cannon_table[force.name] and #global.forces_ion_cannon_table[force.name] > 0 then
+			global.IonCannonLaunched = true
+			script.on_event(defines.events.on_tick, process_tick)
+			break
 		end
 	end
 end
 
+function On_Load()
+	getIonCannonFiredEventID()
+	if global.IonCannonLaunched then
+		script.on_event(defines.events.on_tick, process_tick)
+	end
+end
+
+function getIonCannonFiredEventID()
+	if not when_ion_cannon_fired then
+		when_ion_cannon_fired = script.generate_event_name()
+	end
+	return when_ion_cannon_fired
+end
+
 script.on_event(defines.events.on_force_created, function(event)
 	if not global.forces_ion_cannon_table then
 		On_Init()
@@ -295,6 +317,9 @@ script.on_event(defines.events.on_rocket_launched, function(event)
 	local force = event.rocket.force
 	if event.rocket.get_item_count("orbital-ion-cannon") > 0 then
 	  table.insert(global.forces_ion_cannon_table[force.name], {ionCannonCooldownSeconds, 0})
+	  if not global.IonCannonLaunched then
+		global.IonCannonLaunched = true
+	  end
 	  script.on_event(defines.events.on_tick, process_tick)
 		if #global.forces_ion_cannon_table[force.name] == 1 then
 			force.recipes["ion-cannon-targeter"].enabled = true
@@ -364,6 +389,7 @@ script.on_event(defines.events.on_put_item, function(event)
 				global.forces_ion_cannon_table[player.force.name][cannonNum][1] = ionCannonCooldownSeconds
 				global.forces_ion_cannon_table[player.force.name][cannonNum][2] = 0
 				messageForce({"time-to-ready-again" , cannonNum , ionCannonCooldownSeconds}, player.force)
+				game.raise_event(when_ion_cannon_fired, {force = player.force, player_index = event.player_index, position = TargetPosition})		-- Passes event.force, event.player_index, and event.position
 			end
 		end
 	end

data-updates.lua

@@ -0,0 +1,7 @@
+if data.raw["tool"]["science-pack-4"] and enableBobUpdates then
+	data.raw["technology"]["orbital-ion-cannon"].unit.ingredients[5] = {"science-pack-4", 2}
+end
+
+if not data.raw["assembling-machine"]["assembling-machine-4"] then
+	data.raw["assembling-machine"]["assembling-machine-3"].ingredient_count = 8
+end

data.lua

@@ -3,7 +3,3 @@ require("prototypes.items")
 require("prototypes.entities")
 require("prototypes.recipes")
 require("prototypes.technologies")
-
-if not data.raw["assembling-machine"]["assembling-machine-4"] then
-	data.raw["assembling-machine"]["assembling-machine-3"].ingredient_count = 8
-end

info.json

@@ -1,6 +1,6 @@
 {
   "name": "Orbital Ion Cannon",
-  "version": "1.0.8",
+  "version": "1.0.9",
   "title": "Orbital Ion Cannon",
   "author": "Supercheese",
   "homepage": "http://www.factorioforums.com/forum/viewtopic.php?f=93&t=17910",

prototypes/technologies.lua

@@ -27,10 +27,6 @@ data:extend({
  },
 })
 
-if data.raw["item"]["science-pack-4"] and enableBobUpdates then
-	data.raw["technology"]["orbital-ion-cannon"].unit.ingredients[4] = {"science-pack-4", 2}
-end
-
 if data.raw["item"]["bob-laser-turret-5"] and enableBobUpdates then
 	data.raw["technology"]["orbital-ion-cannon"].prerequisites = {"rocket-silo", "laser-turret-damage-6", "bob-laser-turrets-5"}
 end